grammar - Should you use past tense for a fact that still remains in force?

For example what variant is correct?

• He was the man who did that first.



• He is the man who did that first.





• He himself appeared in a film about his life.




• He himself appears in a film about his life.




• He was the strongest man ever when he was alive.




• He is still the strongest man ever even though he is dead.




• He said this in his letters.




• He says this in his letters.




• In this photo he looked healthy.



• In this photo he looks healthy.

Answer

In most of your sentences, past and present tense are both fine. E.g.:

He said this in his letters.

This is fine, because he wrote the letter in the past.

He says this in his letters.

Even though he died 100 years ago, he still speaks through his letters, so this is also fine.

Be careful with this one:

He himself appeared in a film about his life.

This is okay, but only because the verb appear can mean to take part in a film/movie, play, television programme, etc.

The only one I consider wrong is:

* In this photo he looked healthy.

If you want to use the past tense, you should use appear.

When you say he looks healthy the focus is on you, and your experience. Your experience is happening now, so use the present tense.

When you say he appears / appeared healthy the focus is on him. He appeared healthy at the time the photo was taken and, because the photo has not changed, he still appears healthy now.

In this photo he looks healthy. OK

In this photo he appears healthy. OK

In this photo he looked healthy. WRONG

In this photo he appeared healthy. OK

EDIT

Barrie England points out that, in certain contexts, “In this photo he looked healthy.” is fine. The sense is something like, “As you can see in this photo, he looked healthy in 2000.”